<style>
  p{
    padding: 1px;
  }
  .wrapper {
    color: lightsalmon;
  }
  .name {
    font-family: '黑体';
  }
  /* body{
    background-color: aqua;
  } */
  .aa{
    -webkit-margin-before: 0.67em;
-webkit-margin-after: 0.67em;
 font-size: 2em; 

  }
</style>
<p>
  <div>unset 就是：如果可继承就继承，否则就是initial。可以理解成inherit和initial的综合，优先inherit</div>
  <div class="wrapper">
    <span>this is a</span>
    <span class="name" style="color: unset">unset</span>
    <span>test!</span>
  </div>
  <div class="wrapper">
    <span>this is a</span>
    <span class="name" style="color: initial">initial</span>
    <span>test!</span>
  </div>
</p>

<p>
  <button onclick="downLoad()">下载</button>
</p>

<!-- <h1 style="font-weight: initial; color: unset">H1: unset</h1>
<h1 style="font-weight: revert; color: revert">H1: revert</h1> -->
<script>
  function downLoad(){
    const a =document.createElement('a')
    a.innerText="文件"
    a.download='test.mp3'
    a.href="./x.mp3"
    document.body.appendChild(a)
    a.click()
    console.log('1111')    
  }
</script>

<a href="../abc/dd.html">首页</a>
<div style="background-color: #456;height: 400px;">
  <div style="position: relative; top:50px;left:50px;z-index:-1;background:#efe">
    <span>123</span>
  </div>
</div>
<div class="aa">111</div>
<span style="color: red">I&#8217;m</span style="color:blue"><span>I’m</span>
